Device for reading digital information recorded on an information carrier, and peak detector and information carrier for such a device

• US 5,107,480 A
• Filed: 04/25/1990
• Issued: 04/21/1992
• Est. Priority Date: 10/23/1989
• Status: Expired due to Fees

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Naus, Peter J. A.
• Primary Examiner(s): Envall, Jr., Roy N.
• Assistant Examiner(s): TRAN, THAI Q
• Application Number:
  US07/514,476
• Time in Patent Office: 727 Days
• Field of Search: 369/50, 369/49, 369/48, 369/47, 369/59, 358/315, 360/39
• US Class Current: 369/47.35
• CPC Class Codes: G11B 20/10 Digital recording or reproducing
• CPC Class Codes: H03G 3/3089 Control of digital or coded signals

Abstract

A signal processor produces a digital signal (Vd), which may be derived from digital information recorded on an information carrier, and applies it to a peak detector for generating a control signal (Vr) which corresponds to the peak value of the digital signal. The digital signal is also applied to a digital amplifier whose gain is controllable by the control signal so that the resulting amplified digital signal (Vv) will drive a digital-to-analog converter to the maximum extent of its conversion range, thereby maximizing the analog output signal (Va) of the converter. The peak detector may be adapted to produce the control signal in accordance with a peak code (Vp) already recorded on the information carrier, which peak code is derived therefrom by the signal processor and indicates the peak digital value of the recorded digital information.

Claims

1. In a device for reading digital information recorded on an information carrier, a circuit arrangement comprising:

a signal processor for deriving a digital signal (Vd) from the recorded digital information as it is read from the information carrier;

a digital amplifier coupled to said signal processor for amplifying the digital signal (Vd) to produce an amplified digital signal (Vv), said digital amplifier having a gain which is controllable by a control signal supplied to a control terminal thereof;

a digital-to-analog converter coupled to said digital amplifier for converting the amplified digital signal (Vv) produced thereby to a corresponding analog signal (Va), the analog signal (Va) having a maximum amplitude when the value of said amplified digital signal (Vv) corresponds to a maximum conversion range of said converter; and

a peak detector coupled to said signal processor for deriving from said digital signal (Vd) a peak signal corresponding to a peak value thereof and producing from said peak signal a control signal corresponding thereto, said control signal being supplied to the control terminal of said amplifier to control the gain thereof so that the maximum value of said amplified digital signal (Vv) corresponds to said maximum conversion range of said converter;

whereby said analog signal (Va) will have its maximum amplitude despite changes in the peak value of said digital signal (Vd).

2. A device as claimed in claim 1, characterized in that the digital information recorded on the information carrier includes a peak code indicative of the peak value of said digital signal (Vd), said signal processor is adapted to derive said peak code from said recorded digital information, and said peak detector is adapted to derive said peak signal from the peak code supplied thereto by said signal processor.